DURATIONAL CUES TO WORD BOUNDARIES IN CLEAR SPEECH

One of a listener's major tasks in understanding continuous speech is segmenting the speech signal into separate words. When listening conditions are difficult, speakers can help listeners by deliberately speaking more clearly. In four experiments, we examined how word boundaries are produced in deliberately clear speech. Durational measurements were taken of the pre-boundary syllable, and of pausing (if any) at the boundary, in baseline utterances and in deliberately clear repetitions. We found that speakers do indeed attempt to mark word boundaries in clear (though not in normal) speech; moreover, they differentiate between word boundaries in a way which suggests they are sensitive to listener needs. Previous research has suggested that in English, listeners apply heuristic segmentation strategies which make word boundaries before strong syllables easiest to perceive. When conditions for the listener are difficult, however, speakers pay more attention to marking word boundaries before weak syllables, i.e. they mark just those boundaries which are otherwise particularly hard to perceive. © 1991.